Using sol–gel auto-combustion combined with calcination, spinel zinc ferrite (ZnFe₂O₄) and monoclinic bismuth vanadate (m-BiVO₄) nanopowder were synthesised. On this basis, novel heterojunction-structure monoclinic bismuth vanadate/spinel ferrite ZnFe₂O₄ (BZF) composites were prepared, for the first time, using sol–gel combined with in situ loading. The characteristics of as-prepared materials were ascertained by X-ray diffraction spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and ultraviolet–visible diffuse reflectance spectroscopy. As-prepared pure ZnFe₂O₄ particles were short, rodlike and about 100–200 nm. Pure m-BiVO₄ powder was spindle-like, distributed uniformly and about 150–250 nm. BZF composites were used to degrade methylene orange (MO) under visible-light irradiation. Among as-prepared BZF composites, BZF-15 wt% had optimal photocatalytic activity for degrading MO. The photocatalytic mechanism of the composites was attributed to the effective separation between photo-generated electrons and holes based on the heterojunction energy-band theory.

中文翻译：

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使用m-BiVO4 / ZnFe2O4复合材料增强光催化性能

利用溶胶-凝胶自燃结合煅烧，合成了尖晶石型铁酸锌（ZnFe ₂ O ₄）和单斜晶钒酸铋（m-BiVO ₄）纳米粉。在此基础上，首次采用溶胶-凝胶结合原位加载技术制备了新型异质结结构单斜晶钒酸铋/尖晶石型铁氧体ZnFe ₂ O ₄（BZF）复合材料。通过X射线衍射光谱，扫描电子显微镜，透射电子显微镜，能量色散X射线光谱和紫外可见漫反射光谱确定所制备材料的特性。制备的纯ZnFe ₂ O ₄粒子很短，呈棒状，大约100-200 nm。纯的m-BiVO ₄粉末呈纺锤状，分布均匀，约150-250 nm。BZF复合材料用于在可见光照射下降解亚甲基橙（MO）。在制备的BZF复合材料中，BZF-15 wt％具有降解MO的最佳光催化活性。复合材料的光催化机理归因于基于异质结能带理论的光生电子与空穴之间的有效分离。